String interpolation in Java 14 or 15

Question

Since I am using Java 14 and 15 preview features. Trying to find the string interpolation in java.

The closest answer I found is

String.format("u1=%s;u2=%s;u3=%s;u4=%s;", u1, u2, u3, u4)

Since the answer which I got from lots fo references are old answers asked 4,5 years ago. Is there any update on the string interpolation in java 11,12,13,14,15 equivalent to C#

string name = "Horace";
int age = 34;
Console.WriteLine($"Your name is {name} and your age {age}");

Answer 1

There is something slightly closer; an instance version of String::format, called formatted:

String message = "Hi, %s".formatted(name);

It is similar to String::format, but is more friendly to use in chained expressions.

Answer 2

To my knowledge, there are no updates in the standard java libraries regarding such kind of string formatting.

In other words: you are still "stuck" with either using String.format() and its index based substitution mechanism, or you have to pick some 3rd party library/framework, such as Velocity, FreeMarker, ... see here for an initial overview.

Answer 3

There is no built-in support for that currently, but Apache Commons StringSubstitutor can be used.

import org.apache.commons.text.StringSubstitutor;
import java.util.HashMap;
import java.util.Map;
// ...
Map<String, String> values = new HashMap<>();
values.put("animal", "quick brown fox");
values.put("target", "lazy dog");
StringSubstitutor sub = new StringSubstitutor(values);
String result = sub.replace("The ${animal} jumped over the ${target}.");
// "The quick brown fox jumped over the lazy dog."

This class supports providing default values for variables.

String result = sub.replace("The number is ${undefined.property:-42}.");
// "The number is 42."

To use recursive variable replacement, call setEnableSubstitutionInVariables(true);.

Map<String, String> values = new HashMap<>();
values.put("b", "c");
values.put("ac", "Test");
StringSubstitutor sub = new StringSubstitutor(values);
sub.setEnableSubstitutionInVariables(true);
String result = sub.replace("${a${b}}");
// "Test"